nmzgrep: command not found

Maybe Your $PATH variable doesn't contain the default paths? echo $PATH should give something like:

[root@server ~]# echo $PATH
/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin

If it's empty, You may set the PATH variable with this command

export PATH="/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin"

On Debian possible default full paths are:

/usr/bin/nmzgrep - from package: namazu2-index-tools

You may install the required package with command apt-get install {package}

Error in other languages:
nmzgrep: bevel nie gevind nie
nmzgrep: comandă negăsită
nmzgrep: comando não encontrado
nmzgrep: commande introuvable
nmzgrep: command not found
nmzgrep: käsku ei ole
nmzgrep: không tìm thấy lệnh
nmzgrep: komanda nerasta
nmzgrep: Kommando nicht gefunden.
nmzgrep: kommandot finns inte
nmzgrep: komut yok
nmzgrep: nie znaleziono polecenia
nmzgrep: níor aimsíodh an t-ordú
nmzgrep: no se encontró la orden
nmzgrep: no s'ha trobat l'ordre
nmzgrep: opdracht niet gevonden
nmzgrep: parancs nem található
nmzgrep: perintah tidak ditemukan
nmzgrep: príkaz nenájdený
nmzgrep: příkaz nenalezen
nmzgrep: команда не найдена
nmzgrep: командата не е открита
nmzgrep: 命令找不到
nmzgrep: コマンドが見つかりません